The World Digital Library (WDL) is a project of the U.S. Library of Congress, carried out with the support of the United Nations Educational, Cultural and Scientific Organization (UNESCO), and in cooperation with libraries, archives, museums, educational institutions, and international organizations from around the world.

Over six million images from the Associated Press, one of the largest and oldest news organizations in the world. Images date back to the mid-nineteenth century and more than 3,500 new photographs are added daily.

The Artstor Digital Library is a nonprofit resource that provides over 1.8 million digital images in the arts, architecture, humanities, and sciences with an accessible suite of software tools for teaching and research.

Google provides both basic and advanced image searching for over 1 billion images. Google's Advanced Image Search searching allows you to limit results based on usage rights, by size and quite a bit more.

Flickr provides a search specifically designed to locate works that are offered under the Creative Commons license.

Search.creativecommons.org offers convenient access to search services provided by other independent organizations. Note that selecting different search options within the result list—particularly Image search for Google and Yahoo—may lead to the inclusion of results which are not Creative Commons licensed.